JP6343805B2 - Refrigeration equipment - Google Patents

Description

  The present invention relates to a vapor compressor type refrigeration apparatus.

  Conventionally, a refrigeration system used for an air conditioner or the like has an insulation of a compressor when an overload condition occurs such that the temperature of refrigerant discharged from the compressor exceeds a predetermined reference value due to a change in environmental temperature during operation. Problems occur in terms of reliability, such as deterioration of materials and deterioration of refrigeration oil. In order to solve this problem, the discharge refrigerant temperature has been adjusted by using an electric expansion valve with a variable throttle amount as a throttle mechanism or a variable capacity compressor as a compressor (for example, Patent Document 1). ).

  By using an electric expansion valve with variable throttle, it is possible to control the superheat of the refrigerant sucked by the compressor and the temperature of the refrigerant discharged from the compressor, and operate the refrigeration cycle in an optimal state. Can do. For this reason, the refrigeration apparatus can be operated with high cycle efficiency (COP).

  In addition, by providing a bypass circuit (liquid bypass mechanism) that introduces liquid refrigerant before flowing into the throttle mechanism into the suction port of the compressor, the rise in the temperature of the discharged refrigerant has been suppressed and the reliability of the compressor has been secured. (For example, patent document 2).

  On the other hand, in the refrigeration apparatus, as a refrigerant, an HFC refrigerant is employed as an alternative refrigerant to the HCFC refrigerant, but in addition to protecting the ozone layer, it is necessary to prevent global warming. Therefore, the use of a mixed refrigerant containing R32 and R32, which are refrigerants having a low global warming potential (low GWP) compared to conventional refrigerants (R410A, R407C, etc.) has been proposed.

  When R32 is used in the refrigeration apparatus, the actual cycle efficiency is increased because the theoretical COP and heat transfer rate are higher and the pressure loss is smaller than when conventional refrigerants such as R22, R410A, and R407C are used. However, since R32 has a larger adiabatic index, which is the thermophysical property of the refrigerant, compared to the conventional refrigerant, the refrigerant discharge refrigerant temperature becomes higher by about 10 ° C. or more. In particular, the discharged refrigerant temperature further increases during an overload condition where the outside air temperature is high.

  In the global market, in order to keep the price low, a capillary tube that is a fixed throttle is often used as the throttle mechanism. In that case, it is not possible to adjust the refrigeration cycle to the optimum state of each condition by controlling the superheat of the refrigerant sucked from the compressor, the refrigerant discharge refrigerant temperature, etc. under standard operating conditions or overload operating conditions It was.

JP 2001-174075 A Japanese Utility Model Publication No. 61-101369

When using a R32 single refrigerant or a mixed refrigerant containing R32 as the main component in a refrigeration system that employs a fixed throttle as the throttle mechanism, the flow rate of the capillary tube should be adjusted so that the discharge refrigerant temperature is below the allowable temperature during overload operation. If set, the capillary tube flow rate will be too high under standard operating conditions. For this reason, there is a problem that the refrigeration cycle cannot be adjusted to an optimum state and the refrigeration capacity and cycle efficiency are reduced. In particular, when an R32 single refrigerant or a mixed refrigerant containing R32 as a main component is used, this tendency is greater than when a conventional refrigerant is used.

  In addition, a refrigeration apparatus that employs a liquid bypass mechanism requires an electromagnetic valve that opens when the discharged refrigerant temperature reaches a certain level. In addition, an electric circuit for operating the electromagnetic valve is also required, which has been a factor in increasing costs in manufacturing the refrigeration apparatus.

  The object of the present invention is to increase the discharge refrigerant temperature even in an overload state in which the discharge refrigerant temperature of the compressor exceeds a predetermined reference value without using an expensive electric expansion valve or solenoid valve. It is intended to provide a refrigeration apparatus that suppresses and ensures the reliability of the compressor and that can be operated with high cycle efficiency during standard operation.

  In order to solve the conventional problems, the first invention uses an R32 single refrigerant or a mixed refrigerant mainly composed of R32 as a refrigerant, and connects a compressor, a condenser, a throttling device, and an evaporator in an annular shape. The control valve is provided in parallel with the expansion device, and the control valve includes a first flow path through which the outlet refrigerant of the condenser flows, and a second flow path through which the discharge refrigerant of the compressor flows. When the refrigerant flowing through the second flow path has a temperature equal to or higher than a certain value, the valve body for changing the cross-sectional area of the first flow path and the shape memory alloy spring provided in the second flow path are provided. The shape memory alloy spring is transformed to drive the valve body.

  The second invention uses a R32 single refrigerant or a mixed refrigerant mainly composed of R32 as a refrigerant, and configures a refrigeration cycle by connecting a compressor, a condenser, an expansion device, and an evaporator in an annular shape, and the expansion device A control valve is provided in series with the first flow path through which the outlet refrigerant of the condenser flows, a second flow path through which the discharge refrigerant of the compressor flows, and a flow path disconnection of the first flow path. A valve body that changes an area; and a shape memory alloy spring provided in the second flow path, and the shape memory alloy spring is transformed when the temperature of the refrigerant flowing through the second flow path reaches a predetermined temperature or more. The valve body is driven.

  According to the present invention, even when an overload condition occurs, it is possible to ensure the reliability of the compressor by suppressing the rise in the refrigerant discharge refrigerant temperature, and to operate with high cycle efficiency during standard operation. Can be realized at low cost.

Refrigeration cycle block diagram of the refrigeration system in Embodiment 1 of the present invention The longitudinal cross-sectional view of the control valve in Embodiment 1 of this invention Temperature-strain curve diagram of shape memory alloy spring used for control valve in embodiment 1 of the present invention The longitudinal cross-sectional view of the control valve in Embodiment 1 of this invention Refrigeration cycle block diagram of an air conditioner in Embodiment 2 of the present invention The longitudinal cross-sectional view of the control valve in Embodiment 2 of this invention The longitudinal cross-sectional view of the control valve in Embodiment 2 of this invention

The first invention uses an R32 single refrigerant or a mixed refrigerant mainly composed of R32 as a refrigerant, and configures a refrigeration cycle by connecting a compressor, a condenser, an expansion device, and an evaporator in an annular shape, and the expansion device A control valve is provided in parallel with the control valve. The control valve includes a first flow path through which the outlet refrigerant of the condenser flows, a second flow path through which the discharge refrigerant of the compressor flows, and a flow path disconnection of the first flow path. A valve body that changes an area; and a shape memory alloy spring provided in the second flow path, and the shape memory alloy spring is transformed when the temperature of the refrigerant flowing through the second flow path reaches a predetermined temperature or more. The valve body is driven.

  As a result, it is possible to provide a refrigeration apparatus that can ensure the reliability of the compressor by suppressing an increase in the discharged refrigerant temperature at the time of overload at a low cost and can operate with high cycle efficiency during standard operation. it can.

  The second invention uses a R32 single refrigerant or a mixed refrigerant mainly composed of R32 as a refrigerant, and configures a refrigeration cycle by connecting a compressor, a condenser, an expansion device, and an evaporator in an annular shape, and the expansion device A control valve is provided in series with the first flow path through which the outlet refrigerant of the condenser flows, a second flow path through which the discharge refrigerant of the compressor flows, and a flow path disconnection of the first flow path. A valve body that changes an area; and a shape memory alloy spring provided in the second flow path, and the shape memory alloy spring is transformed when the temperature of the refrigerant flowing through the second flow path reaches a predetermined temperature or more. The valve body is driven.

  As a result, it is possible to provide a refrigeration apparatus that can ensure the reliability of the compressor by suppressing an increase in the discharged refrigerant temperature at the time of overload at a low cost and can operate with high cycle efficiency during standard operation. it can.

  According to a third invention, in the first or second invention, the mixed refrigerant mainly composed of R32 is a mixed refrigerant of R32 and a hydrofluoroolefin.

  As a result, even when a mixed refrigerant of R32 and hydrofluoroolefin is used, the reliability of the compressor is secured by suppressing the increase in the discharge refrigerant temperature at the time of overload at a low cost. A refrigeration apparatus capable of operating with high cycle efficiency can be provided. Furthermore, it is possible to provide a refrigeration apparatus that can reduce the warming coefficient of the refrigerant, has high cycle efficiency, and can reduce the influence of warming.

  In a fourth aspect based on the third aspect, the hydrofluoroolefin is HFO1234yf.

  As a result, even when a mixed refrigerant of R32 and HFO1234yf is used, the reliability of the compressor is ensured by suppressing an increase in the discharge refrigerant temperature at the time of overload at a low cost, and the cycle efficiency at the time of standard operation It is possible to provide a refrigeration apparatus that can be operated at high speed. Furthermore, it is possible to provide a refrigeration apparatus that can reduce the warming coefficient of the refrigerant, has high cycle efficiency, and can reduce the influence of warming.

  In a fifth aspect based on the third aspect, the hydrofluoroolefin is HFO1234ze.

  As a result, even when a mixed refrigerant of R32 and HFO1234ze is used, the reliability of the compressor is ensured by suppressing an increase in the discharge refrigerant temperature at the time of overload at a low cost, and the cycle efficiency during standard operation It is possible to provide a refrigeration apparatus that can be operated at high speed. Furthermore, it is possible to provide a refrigeration apparatus that can reduce the warming coefficient of the refrigerant, has high cycle efficiency, and can reduce the influence of warming.

  In a sixth aspect based on the third aspect, the hydrofluoroolefin is HFO1123.

As a result, even when a mixed refrigerant of R32 and HFO1123 is used, the reliability of the compressor is ensured by suppressing an increase in the discharge refrigerant temperature at the time of overload at a low cost, and the cycle efficiency at the time of standard operation High operation is possible. Furthermore, it is possible to provide a refrigeration apparatus that can reduce the warming coefficient of the refrigerant, has high cycle efficiency, and can reduce the influence of warming.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
The refrigeration apparatus of the present invention will be described below. As an application example of the refrigeration apparatus of the present invention, an air conditioner will be described with reference to FIG. FIG. 1 is a configuration diagram of a refrigeration cycle of an air conditioner according to Embodiment 1 of the present invention.

  The air conditioner according to Embodiment 1 is a so-called separate air conditioner including an outdoor unit 8 installed outdoors and an indoor unit 9 installed indoors. The outdoor unit 8 includes a compressor 1 that compresses the refrigerant, an outdoor heat exchanger 2 that exchanges heat between the refrigerant and the outside air, an outdoor fan 6 that promotes heat exchange between the refrigerant flowing in the outdoor heat exchanger 2 and the outside air, and a throttle device As a capillary tube 3, a control valve 4, and the like. The indoor unit 9 includes an indoor heat exchanger 5 that exchanges heat between the refrigerant and room air, an indoor fan 7 that promotes heat exchange between the refrigerant flowing in the indoor heat exchanger 5 and room air, and the like. The outdoor unit 8 and the indoor unit 9 are connected by a liquid side connecting pipe 21 and a gas side connecting pipe 22.

  During the cooling operation of the air conditioner, the outdoor heat exchanger 2 acts as a condenser, and the indoor heat exchanger 5 acts as an evaporator. A compressor 1, an outdoor heat exchanger 2, a capillary tube 3 as an expansion device, and an indoor heat exchanger 5 are connected in a ring shape by piping to constitute a refrigeration cycle.

  In the refrigeration cycle, difluoromethane (R32) single refrigerant or a mixed refrigerant containing R32 as a main component is enclosed. The mixed refrigerant mainly composed of R32 includes a mixed refrigerant of R32 and 2,3,3,3-tetrafluoro-1-propene (HFO1234yf), and R32 and trans-1,3,3,3-tetrafluoropropene. (HFO1234ze) or a mixed refrigerant of R32 and trifluoroethylene (HFO1123) achieves both the effect of reducing the global warming coefficient of the refrigerant itself and reducing the effect of global warming as a refrigeration cycle due to high cycle efficiency. Is desirable.

  In addition, R32 is 30 wt% or more and 60 wt% or less in the refrigerant used, which is a mixed refrigerant of R32 and HFO1123. By mixing 30 wt% or more of R32 with R1123, the disproportionation reaction of R1123 can be suppressed. In addition, the mixed refrigerant of R32 and HFO1123 has a higher heat insulation index, which is the thermophysical property of the refrigerant, than that of the conventional refrigerant, and thus the refrigerant discharge refrigerant temperature becomes higher. For this reason, the effect that the reliability of a compressor can be ensured by reducing the discharge refrigerant temperature under an overload condition greatly affects.

  In this refrigeration apparatus, the expansion device is a capillary tube 3, and the control valve 4 is connected in parallel with the capillary tube 3. The control valve 4 includes a first flow path 14 through which the outlet refrigerant of the condenser flows and a second flow path 15 through which the discharge refrigerant of the compressor 1 flows. That is, the first flow path 14 of the control valve 4 branches from the outlet of the outdoor heat exchanger 2 and the inlet of the capillary tube 3 and is connected to a bypass circuit that joins the outlet of the capillary tube 3 and the liquid side connection pipe 21. Has been. The second flow path 15 of the control valve 4 is connected between the outlet of the compressor 1 and the outdoor heat exchanger 2.

FIG. 2 is a longitudinal sectional view of the control valve 4 used in the refrigeration apparatus in the first embodiment. In FIG. 2, 10 is a valve body, 11 is a valve seat, 12 is a bias spring, 13 is a shape memory alloy spring, 14 is a first flow path, 15 is a second flow path, 16 is a bias spring 12 and a shape memory alloy spring. 13 is a valve drive body that is driven by a difference in spring force of 13 and is a magnetic body. The valve body 10 is a valve drive body 1 which is a magnetic body.
It moves according to the movement of 6.

  The control valve 4 includes a substantially cylindrical main body 41 constituting an outer shell, a substantially cylindrical partition body 42 provided in the main body 41 and having an outer diameter smaller than the inner diameter of the main body 41, and both sides of the main body 41 and the partition body 42. Has a side plate that closes each end. The first flow path 14 is a cylindrical flow path formed by a substantially sealed space formed by the inner wall of the partition 42 and the two side plates. The second flow path 15 is an annular column-shaped flow path formed by a substantially sealed space formed by the inner wall of the main body 41, the outer wall of the partition 42, and two side plates. The side plates of the first flow path 14 and the second flow path 15 are respectively provided with an inlet portion and an outlet portion to which piping is connected. The side plate on the side where the outlet portion of the second flow path 15 is provided is provided with a valve seat 11 which is a hole having a tapered side surface.

  A valve body 10 that changes the cross-sectional area of the first flow path 14 is provided in the first flow path 14. The valve body 10 includes a disc-shaped valve body base portion 10a that moves while sliding in the central axis direction within the partition body 42, a truncated cone-shaped valve portion 10b that faces the taper shape of the valve seat 11, and a valve body base portion. 10a and a shaft for connecting the valve portion 10b. The valve body base portion 10a is provided with a first flow hole 10c through which the refrigerant flows from the inlet portion to the outlet portion of the first flow path 14. Of the valve body 10, at least the valve body base portion 10 a is formed of a magnetic material that receives the magnetic force generated by the valve driver 16.

  An annular valve driver 16 that moves while sliding in the central axis direction between the main body 41 and the partition 42 is provided in the second flow path 15. The valve driver 16 is provided with a second flow hole 16 a through which the refrigerant flows from the inlet portion to the outlet portion of the second flow path 15. A coil spring-shaped bias spring 12 is provided between the valve driver 16 and one side plate of the second flow path 15. A shape memory alloy spring 13 having a coil spring shape is provided between the valve driver 16 and the other side plate. The shape memory alloy spring 13 is exposed to the refrigerant flowing through the second flow path 15, that is, the refrigerant discharged from the compressor 1, and transforms when the refrigerant discharged from the compressor 1 reaches a certain temperature.

  The valve driver 16 moves in the body 41 in the axial direction by the balance of the displacement amount of the bias spring 12 and the shape memory alloy spring 13. As the valve drive body 16 that is a magnetic body moves, the valve body 10 formed of a magnetic body moves in the partition 42 in the axial direction. Thereby, the clearance gap formed between the valve part 10b and the valve seat 11 changes.

  FIG. 3 is a temperature-strain curve (hysteresis curve) of the shape memory alloy spring 13. There is a temperature difference between the operating temperature during heating and cooling, that is, temperature hysteresis, and the shape memory alloy spring 13 has a transformation temperature T1 during heating (eg, 110 ° C.) and a transformation temperature T 2 during cooling (eg, 90 ° C.). It is adjusting.

  In the above configuration, the operation of the control valve 4 will be described. When the discharge refrigerant temperature of the compressor 1 rises, the shape memory alloy spring 13 expands when the temperature exceeds the set transformation temperature T1 and pushes the valve driver 16 against the spring force of the bias spring 12. The valve body 10 also moves in accordance with the movement, and the first flow path 14 is opened as shown in FIG. Therefore, a part of the outlet refrigerant of the outdoor heat exchanger 2 that is a condenser flows through the first flow path 14, and the refrigerant flowing through the capillary tube 3 decreases.

  On the other hand, when the discharge refrigerant temperature of the compressor 1 decreases and becomes lower than the set transformation temperature T2, the shape memory alloy spring 13 is deformed and the valve driver 16 is pushed by the bias spring 12. Accordingly, the valve portion 10b of the valve body 10 is pressed against the valve seat 11, and the first flow path 14 is closed as shown in FIG. Therefore, the refrigerant can flow only to the capillary tube 3.

  The operation of the air conditioner configured as described above will be described. First, the normal operation state will be described by taking cooling operation as an example. In a normal operation state, the control valve 4 is closed because the refrigerant discharge temperature of the compressor 1 is lower than the set transformation temperature T2. The refrigerant compressed by the compressor 1 becomes a high-temperature and high-pressure refrigerant, flows into the outdoor heat exchanger 2, promotes heat exchange with the outside air by the outdoor fan 6, dissipates heat, becomes a high-pressure liquid refrigerant, and is sent to the capillary tube 3. . At this time, the control valve 4 is closed.

  In the capillary tube 3, the refrigerant is depressurized to become a low-temperature and low-pressure two-phase refrigerant, which is sent to the indoor heat exchanger 5 through the liquid side connection pipe 21.

  The indoor air sucked by the indoor fan 7 passes through the indoor heat exchanger 5 and exchanges heat with the low-temperature and low-pressure two-phase refrigerant, and the refrigerant absorbs the heat of the indoor air and evaporates and becomes a low-temperature gas refrigerant. At this time, the indoor air absorbed by the refrigerant is lowered in temperature and humidity and blown out into the room by the indoor fan 7 to cool the room. Further, the gas refrigerant passes through the gas side connecting pipe 22 and returns to the compressor 1.

  Next, the operation state at the time of overload operation, such as a state with high outdoor temperature, is demonstrated. During the cooling operation, when the outdoor air temperature is high and the temperature of the refrigerant discharged from the compressor 1 flowing through the second flow path 15 of the control valve 4 is higher than the set transformation temperature T1, the shape memory alloy spring 13 is a spring force of the bias spring 12. The bias driver 12 is compressed by pushing the valve driver 16 against the above. For this reason, the valve body 10 moves according to the movement of the valve drive body 16 which is a magnetic body, and the first flow path 14 is opened. As a result, the refrigerant flow path through which the refrigerant discharged from the compressor 1 flows increases in both the first flow path 14 and the capillary tube 3. For this reason, the refrigerant flowing through the capillary tube 3 decreases. As a result, the amount of decompression at the expansion device decreases, and the discharged refrigerant temperature decreases.

  Further, when the temperature of the refrigerant discharged from the compressor 1 flowing through the second flow path 15 of the control valve 4 becomes lower than the set transformation temperature T2 of the shape memory alloy spring 13, the shape memory alloy spring 13 is deformed again as shown in FIG. The valve driver 16 is pushed by the bias spring 12. Accordingly, the valve portion 10b of the valve body 10 is pressed against the valve seat 11, and the first flow path 14 is closed. The refrigerant can only flow through the capillary tube 3, and the pressure difference between the front and rear of the throttle device increases, realizing an optimal refrigeration cycle and improving cycle efficiency.

  As described above, when the outdoor air temperature is very high and the temperature of the refrigerant discharged from the compressor 1 becomes high, the refrigerant flow rate of the expansion device increases, and the temperature of the refrigerant discharged from the compressor 1 decreases. On the other hand, when the outside air temperature is a normal temperature, the flow rate of the normal throttle device can be controlled, and a cooling operation with high cycle efficiency is possible.

(Embodiment 2)
FIG. 5 is a refrigeration cycle diagram in the second embodiment of the refrigeration apparatus of the present invention. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In FIG. 5, the second control valve 19 is a control valve connected in series with the capillary tube 3. That is, the first flow path 14 of the second control valve 19 is connected between the outlet of the capillary tube 3 and the liquid side connection pipe 21. The second flow path 15 of the second control valve 19 is connected between the outlet of the compressor 1 and the outdoor heat exchanger 2.

  The second control valve 19 is different in structure from the control valve 4 described in the first embodiment and includes a pressure reducing mechanism.

FIG. 6 is a longitudinal sectional view of the second control valve 19. In FIG. 6, the valve body 10 includes a valve body base 1.
A third flow path 20 is provided in communication with the shaft connecting 0a and the valve portion 10b. One end of the third flow path 20 opens to the side where the valve portion 10b of the valve body base portion 10a is not provided, and the other end opens to the top surface of the truncated cone shape of the valve portion 10b. The temperature-strain curve (hysteresis curve) of the shape memory alloy spring 13 is the same as that of the first embodiment shown in FIG.

  In the above configuration, the operation of the second control valve 19 will be described. When the discharge refrigerant temperature of the compressor 1 rises, the shape memory alloy spring 13 expands when the temperature exceeds the set transformation temperature T1 and pushes the valve driver 16 against the spring force of the bias spring 12. The valve body 10 also moves in accordance with the movement, and the first flow path 14 is opened as shown in FIG. At this time, in the first flow path 14, the refrigerant can flow through the first flow hole 10 c and the third flow path 20.

  On the other hand, when the discharge refrigerant temperature of the compressor 1 decreases and becomes lower than the set transformation temperature T2, the shape memory alloy spring 13 is deformed, and the valve driver 16 is pushed by the bias spring 12. Accordingly, the valve portion 10 b of the valve body 10 is pressed against the valve seat 11. Thereby, in the 1st flow path 14, a refrigerant | coolant cannot flow through the 1st flow hole 10c, but will flow through only the 3rd flow path 20. FIG. Therefore, the flow path of the outlet refrigerant of the outdoor heat exchanger 2 that flows through the second control valve 19 is narrowed, so that the pressure is reduced.

  Next, the operation of the air conditioner will be described. In a normal operation state, since the discharged refrigerant temperature of the compressor 1 is lower than the set transformation temperature T2, the second control valve 19 is in a state where the valve body 10 is pressed against the valve seat 11.

  In an operating state during an overload operation such as a high outdoor air temperature, when the temperature of the refrigerant discharged from the compressor 1 flowing through the second flow path 15 of the second control valve 19 is higher than the set transformation temperature T1, FIG. As described above, the shape memory alloy spring 13 pushes the valve driver 16 against the spring force of the bias spring 12 to compress the bias spring 12. For this reason, the valve body 10 moves according to the movement of the valve drive body 16 which is a magnetic body, and the first flow path 14 is opened. Since the refrigerant flows through the first flow hole 10 c and the third flow path 20, the refrigerant is not decompressed by the second control valve 19, and there is no refrigerant temperature difference before and after the second control valve 19. As a result, the discharge refrigerant temperature of the compressor 1 can be lowered.

  When the temperature of the refrigerant discharged from the compressor 1 flowing through the second flow path 15 of the second control valve 19 becomes lower than the set transformation temperature T2 of the shape memory alloy spring 13 due to, for example, the outdoor air temperature becoming lower, FIG. Thus, the shape memory alloy spring 13 is deformed, and the valve driver 16 is pushed by the bias spring 12. Accordingly, the valve portion 10 b of the valve body 10 is pressed against the valve seat 11. As a result, the refrigerant cannot flow through the first flow hole 10c, but can flow only through the third flow path 20, and the flow path is narrowed. For this reason, a pressure difference arises before and behind the 2nd control valve 19, a pressure difference becomes large before and behind a throttle device, an optimal refrigerating cycle is realized, and cycle efficiency improves.

  Thus, by using the second control valve 19 which is a control valve having a pressure reducing mechanism, the temperature of the refrigerant discharged from the compressor 1 exceeds a predetermined reference value due to a change in the environmental temperature at a low cost. Even in a load state, the increase in the refrigerant temperature discharged from the compressor 1 is suppressed to ensure the reliability of the compressor 1 and to enable operation with high cycle efficiency.

  In addition, although the above embodiment demonstrated the operation | movement and effect at the time of air_conditioning | cooling operation of an air conditioner, it is good also as a structure which can provide a four-way valve in a refrigeration apparatus and can also perform heating operation. In this case, the outdoor heat exchanger 2 acts as an evaporator, and the indoor heat exchanger 5 acts as a condenser. Even when the refrigerant discharge temperature of the compressor 1 exceeds a predetermined reference value during the heating operation, the control valve 4 and the second control valve 19 operate to discharge the compressor 1 The rise in the refrigerant temperature can be suppressed, the reliability of the compressor 1 can be ensured, and the operation with high cycle efficiency can be enabled.

  In addition, the same effect can be obtained in a refrigeration apparatus other than an air conditioner.

  According to the present invention, it is possible to improve the reliability of the compressor by suppressing an increase in the refrigerant discharge refrigerant temperature and to provide a refrigeration apparatus with high cycle efficiency. It can be applied to water heaters for automobiles and air conditioners for automobiles.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Outdoor heat exchanger 3 Capillary tube 4 Control valve 5 Indoor heat exchanger 6 Outdoor fan 7 Indoor fan 8 Outdoor unit 9 Indoor unit 10 Valve body 10a Valve body base part 10b Valve part 10c 1st flow hole 11 Valve seat 12 Bias spring 13 Shape memory alloy spring 14 First flow path 15 Second flow path 16 Valve driver 16a Second flow hole 19 Second control valve 21 Liquid side connection pipe 22 Gas side connection pipe 41 Main body 42 Partition body

Claims (6)

A R32 single refrigerant or a mixed refrigerant mainly composed of R32 is used as a refrigerant, and a compressor, a condenser, a throttle device, and an evaporator are connected in a ring to form a refrigeration cycle, and a control valve is provided in parallel with the throttle device. The control valve includes a first flow path through which the outlet refrigerant of the condenser flows and a second flow path through which the discharge refrigerant of the compressor flows, and the first flow path is provided in the first flow path. It provided the valve for varying the passage sectional area, the provided and shape memory alloy spring and the valve drive member to the second flow path, and wherein the shape memory alloy spring and the valve driving body is coupled, the second The refrigeration apparatus, wherein the shape memory alloy spring is transformed to move the valve driving body when the refrigerant flowing through the flow path reaches a certain temperature or more, and the valve body is driven according to the movement of the valve driving body . A R32 single refrigerant or a mixed refrigerant containing R32 as a main component is used as the refrigerant, and a compressor, a condenser, a throttle device, and an evaporator are connected in a ring to form a refrigeration cycle, and a control valve is connected in series with the throttle device. The control valve includes a first flow path through which the outlet refrigerant of the condenser flows and a second flow path through which the discharge refrigerant of the compressor flows, and the first flow path is provided in the first flow path. It provided the valve for varying the passage sectional area, the provided and shape memory alloy spring and the valve drive member to the second flow path, and wherein the shape memory alloy spring and the valve driving body is coupled, the second The refrigeration apparatus, wherein the shape memory alloy spring is transformed to move the valve driving body when the refrigerant flowing through the flow path reaches a certain temperature or more, and the valve body is driven according to the movement of the valve driving body . The refrigeration apparatus according to claim 1 or 2, wherein the mixed refrigerant containing R32 as a main component is a mixed refrigerant of R32 and hydrofluoroolefin. The refrigeration apparatus according to claim 3, wherein the hydrofluoroolefin is HFO1234yf. The refrigeration apparatus according to claim 3, wherein the hydrofluoroolefin is HFO1234ze. The refrigeration apparatus according to claim 3, wherein the hydrofluoroolefin is HFO1123.